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Modification of reactively sputtered NiO x thin films by pulsed UV laser irradiation
Author(s) -
Itapu Srikanth,
Georgiev Daniel G.,
Uprety Prakash,
Podraza Nikolas J.
Publication year - 2017
Publication title -
physica status solidi (a)
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.532
H-Index - 104
eISSN - 1862-6319
pISSN - 1862-6300
DOI - 10.1002/pssa.201600414
Subject(s) - materials science , irradiation , thin film , amorphous solid , sputtering , ultraviolet , ellipsometry , laser , non blocking i/o , crystallite , analytical chemistry (journal) , nickel oxide , optoelectronics , nickel , optics , nanotechnology , metallurgy , chemistry , crystallography , physics , biochemistry , chromatography , nuclear physics , catalysis
This work reports on the effect of ultraviolet (UV) laser irradiation on the structural, electrical, and optical properties of nickel oxide (NiO x ) thin films, deposited by reactive sputtering of nickel in an oxygen containing atmosphere. It was found that the conduction type can be changed from p‐type to n‐type and the resistivity decreased as the number of laser pulses is increased and then increases again. The as‐deposited films are polycrystalline, while laser irradiation renders the films amorphous. The observed transition from O‐rich NiO x as‐deposited films to Ni‐rich laser‐irradiated NiO x can be significant to electrochromic, resistive switching, and other applications. The band gap of the as‐deposited and the laser irradiated NiO x films was obtained from spectroscopic ellipsometry measurements and was found to slightly increase upon laser irradiation. It is also observed that the surface roughness increases slightly. Aging effects or instabilities in the structure and composition of the films are also observed under normal conditions.